Surface Water Quality Assessment of Lakhisarai Stretch of Kiul River in Bihar

The Kiul River holds significant importance for the district of Lakhisarai, Bihar. It plays a crucial role in the local ecology, supporting agriculture and serving as a vital water resource for the community. The presence of river has been a decisive factor for the socio-economic fabric of the Lakhisarai District. The research aimed to identify and assess the Water Quality Index using eight parameters pH, turbidity, total dissolved solids (TDS), biological oxygen demand (B.O.D), dissolved oxygen (DO), electrical conductivity (EC), iron (Fe), and zinc (Zn), which are crucial water quality indicators. B.O.D reflects organic pollution levels, DO measures oxygen available for aquatic life, and turbidity measures the presence of suspended particles and other parameters to determine the water quality at eight different locations (S1–S8) along the river Kiul flowing within the Lakhisarai stretch. The study utilized the Weighted Arithmetic Water Quality Index (WAWQI) to compute the Water Quality Index. The findings showed significant turbidity fluctuations in the post-monsoon, surpassing permissible limits in both seasons. Additionally, post-monsoon iron content exceeded permissible levels. Certain stations experienced fluctuations in electrical conductivity also. This was due to inadequate sanitation, turbulent flow, soil erosion, and heightened human activities, including sand mining, urbanization, and open dumping along the riverbanks. Pre-monsoon Water Quality Index (WQI) was relatively safe, but post-monsoon results were detected beyond permissible level. Effective treatment and purification processes are suggested for meeting human needs.